Genetics and Evolution
Genetics and Evolution

Genetics and Evolution

Lead Author(s): Saylor Academy

Source: Saylor

Student Price: FREE

A multiple choice question pack on general genetics and Evolution topics.

This content is licensed under the Creative Commons Attribution 3.0 Unported License.

Question 1
question description

Consider this Punnett Square and the space that has been left blank (with question marks). If the dominant phenotype for trait "A" is red eyes and the recessive phenotype is white eyes, what color eyes will individuals with the genotype from the unfilled-in column have?

A

White Eyes

B

Red Eyes

C

Pink Eyes

D

This cannot be determined from the information given.

Question 2
question description

Consider this Punnett Square. What do the boxes with two letters in each represent?

A

The phenotype of two individuals' offspring.

B

The sound Mendel made when he saw that his pea predictions were correct.

C

The genotype of two individuals' offspring.

D

The homozygous dominant genotype.

Question 3

For an autosomal trait that displays typical Mendelian inheritance, you would expect a phenotypic ratio of 3:1 in offspring if the individuals that mated:

A

Were each heterozygous for that trait.

B

Were a heterozygous individual and a homozygous recessive individual.

C

Were each homozygous recessive for that trait.

D

Were made up (that is, the ratio is not possible).

Question 4

For an autosomal trait that displays typical Mendelian inheritance: you would expect a phenotypic ratio of 1:1 in offspring if the individuals that mated:

A

Were each heterozygous for that trait.

B

Were a heterozygous individual and a homozygous recessive individual.

C

Were each homozygous recessive for that trait

D

Were made up (that is, the ratio is not possible).

Question 5

In the coral-reef Punk Blenny (a fish), purple head color is the dominant trait and magenta head color is the recessive. In which of the following cases would you know the fish's phenotype and genotype?

A

It is the offspring of two purple-headed blennies and has a purple head.

B

It is the offspring of a heterozygous mother and a homozygous recessive father.

C

It is the offspring of a homozygous dominant mother and a homozygous recessive father.

D

It has a purple head.

Question 6

In the speckled YakkityYak bird, speckles and the song "don'ttalkback" are dominant traits while no speckles and the song "yakkityyakkity" are recessive traits. You cross a bird that is heterozygous for speckling and recessive for song with a bird that is heterozygous for all traits. What proportion of their offspring will sing "yakkityyakkity"?

A

1/16.

B

4/16

C

6/16.

D

8/16

Question 7

Which of the following is a part of Mendel's Law of Segregation?

A

Genes that affect more than one phenotype can be lethal.

B

Each gamete only carries one allele for a particular trait.

C

Genes that interact together may not assort independently.

D

Recessive alleles for different traits are generally segregated from one another.

Question 8

Which of these is NOT one of the reasons why Mendel would have had difficulty reaching his conclusions if he had studied height in humans instead of seed traits in pea plants?

A

Humans have much longer generation times than pea plants.

B

Height in humans is X-linked.

C

Height in humans is polygenic.

D

Humans cannot self-pollinate (or reproduce asexually as well as sexually).

Question 9

Which of these statements is NOT true about Mendel's work:

A

It was immediately recognized as a breakthrough by the scientific community

B

It involved the study of traits that were present in discrete, rather than continuous, forms.

C

It provided evidence for the fact that offspring receive one copy of an allele from each parent.

D

It provided evidence for the fact that alleles for different traits assort independently.

Question 10

You know that tufted feet in chickens is a dominant trait. You have a rooster with tufted feet but don't know its genotype. So you perform a test cross to find out. That means that:

A

You cross the rooster with a hen that you know is heterozygous recessive.

B

You cross the rooster with a hen that you know is homozygous recessive.

C

You cross the rooster with a hen of unknown parentage and tufted feet.

D

You cross the rooster with another rooster (just to be safe).

Question 11

A woman who is a carrier (heterozygous) for a recessive disease marries a man who is also a carrier. What is the likelihood that their child will be both healthy and not a carrier of the disease?

A

0 out of 4.

B

1 out of 4.

C

2 out of 4.

D

3 out of 4.

Question 12

A woman who is a carrier (heterozygous) for a recessive disease marries a man who is also a carrier. What is the likelihood that their child will have the disease? (Note: carriers are healthy.)

A

0 out of 4

B

1 out of 4

C

2 out of 4

D

3 out of 4

Question 13

Color-blindness is a sex-linked (also called X-linked) trait in humans. If a woman who is a carrier for color-blindness has children with a man who is colorblind, what is true about their sons?

A

Any son they have would be colorblind.

B

No son they have would be colorblind.

C

They have a 75% chance of having a colorblind son.

D

They have a 50% chance of having a colorblind son.

Question 14

Color-blindness is a sex-linked (also called X-linked) trait in humans. If a woman who is a carrier for color-blindness has children with a man who is colorblind, what is true about their daughters?

A

Any daughter they have would be colorblind.

B

No daughter they have would be colorblind.

C

Any daughter they have will either be a carrier or colorblind.

D

They have a 25% chance of having a colorblind daughter.

Question 15

Color-blindness is a sex-linked (also called X-linked) trait in humans. A woman who is a carrier for color-blindness has children with a man who is colorblind. Their son, Frank, marries a woman who is neither colorblind nor a carrier. Their daughter, Mariana, marries a man who is colorblind. Which of the following is a certainty (not just possible, but certain to be true)?

A

All of Frank's sons will be colorblind

B

All of Frank's daughters will be carriers.

C

None of Frank's sons will be colorblind.

D

None of Mariana's daughters will be carriers.

Question 16

In humans, the gene for curly hair is incompletely dominant to the gene for straight hair. What would be the phenotypic proportions of the children of two individuals that are heterozygous for the trait (have wavy hair)?

A

1/2 would have wavy hair and 1/2 would have straight hair.

B

1/4 would have curly hair, 1/4 would have wavy hair, and 1/2 would have straight hair.

C

1/4 would have curly hair, 1/2 would have wavy hair, and 1/4 would have straight hair.

D

All children would have wavy hair.

Question 17

In snapdragons, the gene for red petal color is incompletely dominant to the gene for white petal color (the phenotype for heterozygous individuals is pink petals). If a plant with pink petals was crossed with a plant with white petals, what would be the proportions of flower-petal types in their offspring?

A

1/4 would have red petals, 1/2 would have pink petals, and 1/4 would have white petals.

B

1/2 would have red petals and 1/2 would have white petals.

C

1/2 would have red petals and 1/2 would have pink petals.

D

1/2 would have pink petals and 1/2 would have white petals.

Question 18

The Chromosome Theory of Inheritance (1903, proposed by Walter Sutton and Theodore Boveri):

A

States that chromosomes recombine, thus explaining how genetic variation is inherited.

B

Argues that chromosomes were elements entirely separate from genes which functioned as the basic unit of inheritance.

C

States that chromosomes are physical elements of cells and contain genes, thus explaining how the process of inheritance occurs.

D

Has been discredited by modern science.

Question 19

Which of the following is NOT true of sex and sex-linked ("X-linked") traits in humans?

A

Females are the heterogametic sex (the sex with two different chromosomes).

B

Males cannot inherit such traits from their fathers.

C

The expression of such traits is often more common in men than women.

D

For individuals with two X chromosome, one copy is turned off in each cell.

Question 20

Which of the following is true of Meiosis I?

A

It results in the production of four haploid daughter cells.

B

DNA is replicated during Metaphase.

C

It allows for crossing over between homologous chromosomes.

D

It is the most common type of cell division in eukaryotic cells.

Questions 21

Why is meiosis like democracy, according to Professor Stearns?

A

Just as democracy was developed using a small group of individuals representing a larger group's interest, meiosis developed as a means of representing all stem-cell-level genes within gametes.

B

Just as democracy developed to prevent political cheating, meiosis developed as a means to prevent meiotic drivers from increasing their genes' chance of being inherited.

C

Just as democracy requires the consensus of a majority, meiosis requires the involvement of many intracellular components.

D

Just as democracy involves plurality and multiplicity, meiosis ensures variation.

Question 22

Your mother's blood type is A and your father's is B. Your blood type could be:

A

A

B

AB

C

O

D

Any of the above.

Question 23

A male limpet chooses a very large female to be his mate because large females maintain better territories than small females. Which of these types of sexual selection is operating?

A

Direct benefits.

B

"Good genes."

C

Runaway selection.

D

"Sexy sons."

Question 24

According to Rudyard Kipling's (very fictional) Just So Stories, the original Whale tried to eat a man, and in revenge the man stuck a grate in the whale's throat that prevented it from eating anything but very small fish-and that is why today's (baleen) whales, too, only eat tiny fish and crustaceans. Is this model more similar to Darwin's evolutionary model or Lamark's-and why?

A

Darwin's, because it addresses the concept of evolutionary change occurring over many generations.

B

Lamarck's, because it deals with the concept of offspring inheriting acquired characteristics.

C

Darwin's, because it posits a specific hypothesis in order to explain an adaptation.

D

Lamarck's, because it reflects the belief, common at that time, that evolution was a punishment inflicted on poorly-behaved species.

Question 25

Flowers whose throats (nectaries) are too long for potential pollinators to reach their nectar are unlikely to be pollinated and therefore unlikely to reproduce. But if the nectarines are too short, animals can get their nectar without pollinating them. This is an example of what sort of selection?

A

Disruptive.

B

Stabilizing.

C

Directional.

D

Sexual.

Question 26
question description

This graph illustrates what type of selection? (The unbroken line represents the first generation; the dashed line represents later generations.

A

Disruptive.

B

Stabilizing.

C

Directional.

D

Sexual.

Question 27
question description

This graph illustrates which type of selection? (The unbroken line represents the first generation; the dashed line represents later generations.)

A

Disruptive

B

Stabilizing.

C

Directional.

D

Sexual.

Question 28

This graph illustrates which type of selection? (The unbroken line represents the first generation; the dashed line represents later generations.)

A

Disruptive.

B

Stabilizing.

C

Directional.

D

Sexual.

Question 29

Which of following is NOT a prediction of Darwin's that has been supported by later discoveries and research?

A

Darwin suspected that nature did not make leaps and that gaps in the fossil record would be filled, better supporting his argument for evolution; since then, transitional fossils have been found for many species.

B

Darwin suspected that humans were animals (an unpopular idea at the time); since then, geneticists have found that the genomes of all living things include some genes that are shared across all kingdoms, proving our common ancestry.

C

Darwin suspected that understanding embryonic development would illuminate evolution; since then, developmental biologists have discovered that much variation is caused by shared "master genes" which are turned on and off in different ways for different organisms.

D

All of these are predictions of Darwin's.

Question 30

Which type of sexual selection has the greatest potential to become at odds with natural selection?

A

Direct benefits.

B

"Good genes."

C

Runaway selection.

D

"Sexy sons."

Question 31

You observe that mussels growing at Halibut Point State Park have much thicker shells than do mussels growing at the Plymouth pier. You also observe that there are many more predatory snails, which feed on mussels by drilling through their shells, present at Halibut Point than in Plymouth. Assuming that these differences are the result of selection, what type of selection is acting on the mussels at Halibut Point?

A

Disruptive selection.

B

Directional selection.

C

Stabilizing selection.

D

Sexual selection.

Question 32

You observe that mussels growing at Halibut Point State Park have much thicker shells than do mussels growing at the Plymouth pier. You also observe that there are many more predatory snails, which feed on mussels by drilling through their shells, present at Halibut Point than in Plymouth. There is some doubt as to whether the differences you've observed are due to natural selection or are the result of phenotypic plasticity. Which of the following studies and results would convince you that the differences are due to natural selection?

A

You survey five more mussel populations and find that in every case where there are predatory snails present, mussels' shells are much thicker.

B

You raise offspring of mussels from both populations in the lab, without any predators present, and find that none of the offspring grow thick shells.

C

You transfer adult snails from the Plymouth population to Halibut Point and find that they are eaten more than native mussels are.

D

You raise offspring of mussels from both populations in the lab, without any predators present, and find that the offspring of Halibut-Point mussels grow thicker shells.

Question 33

You observe that mussels growing at Halibut Point State Park have much thicker shells than do mussels growing at the Plymouth pier. You also observe that there are many more predatory snails, which feed on mussels by drilling through their shells, present at Halibut Point than in Plymouth. Which of the following studies and results would convince you that the differences are due to phenotypic plasticity?

A

You survey five more mussel populations and find that in every case where there are predatory snails present, mussels' shells are much thicker.

B

You raise offspring of mussels from both populations in the lab, without any predators present, and find that none of the offspring grow thick shells.

C

You transfer adult snails from the Plymouth population to Halibut Point and find that they are eaten more than native mussels are.

D

You raise offspring of mussels from Plymouth in the lab in the presence of snail predators and find that none of the offspring grow thick shells.

Question 34

You observe that mussels growing at Halibut Point State Park have much thicker shells than do mussels growing at the Plymouth pier. You also observe that there are many more predatory snails, which feed on mussels by drilling through their shells, present at Halibut Point than in Plymouth. Why might greater shell-thickness in mussels be an induced rather than a constitutive (always present) trait?

A

The cost of making a thicker shell is too great to be worth doing except in the presence of many snail predators.

B

Selection can only act on induced traits.

C

Constitutive shell thickness results in less genetic variability, leading to less variation in shell thickness for the next generation.

D

Induced traits are expressed more strongly than constitutive traits, making the mussels less vulnerable to predators.

Question 35

A group of researchers conducted genetic analyses of a population of turtles in upper New York State. They found that the turtles' gene frequencies and genotype ratios fluctuated considerably over several generations. Given what you know about the Hardy-Weinberg equilibrium, which of these is NOT a possible reason for their results?

A

The turtle population is located in a pond that connects to a series of rivers, allowing many turtles to enter and leave the population each year.

B

Among this population of turtles, males exhibit a preference for females with rougher shells.

C

Researchers found a remarkably low level of genetic mutation across generations of these turtles.

D

Slower-growing juvenile turtles are more regularly eaten by fish predators than faster-growing juveniles.

Question 36

In cases where the assumptions of Hardy-Weinberg equilibrium are met, why will a recessive trait that is present at a very low frequency remain in a population instead of disappearing over generations?

A

Most recessive alleles are beneficial and so are therefore selected for.

B

Mutations will lower the frequency of the dominant allele by changing it to the recessive, thus keeping the recessive trait in the population.

C

The recessive allele is also present in heterozygous individuals, ensuring that the trait will reappear in further generations.

D

Immigration of individuals with the recessive trait will increase its frequency in a population.

Question 37

In general, across all species on the planet, which has been more important for the maintenance of genetic variation: selection or genetic drift?

A

Genetic drift.

B

Selection.

C

Neither one is responsible for the majority of observed variation.

D

Both are very important; usually it is impossible to tell which is more important.

Question 38

What is a long-term evolutionary benefit for populations that are in Hardy-Weinberg equilibrium?

A

The population will maintain genetic variability, ensuring that there will be variation for any future selective forces to act on.

B

Alleles present at high frequencies will remain present at high frequencies, ensuring that assortative mating can occur between individuals with similar phenotypes.

C

The population will have reduced genetic variability, ensuring that deleterious traits will not increase in frequency.

D

The population will by definition not be affected by natural selection, ensuring that they are less likely to be affected by mutations or disease.

Question 39

Which of the following DOES NOT explain why genetic variation can be neutral?

A

Some mutations in DNA end up coding for the same amino acid as the original code.

B

Some amino acids are interchangeable within proteins; if one is substituted for the other, the protein remains functional.

C

Some mutations are lethal and gametes with such mutations cannot develop to adulthood.

D

Some areas of DNA are never transcribed.

Question 40

Which of the following is an example of a population bottleneck and its effects?

A

Only twelve people, one of whom has a rare allele, survive a crash-landing on an uninhabited island. Four hundred years later, a huge proportion of the island's inhabitants have this rare allele.

B

A species of South American monkey is hunted to near extinction. One hundred years later, the monkeys' abundance has increased, but each individual is a near genetic twin of every other monkey.

C

A population of guppies in a large lake becomes divided when an earthquake causes a barrier to form, splitting the lake in half. Many generations later, the guppies in one half are all bright-colored and those in the other are all dull-colored.

D

Being heterozygous for sickle-cell anemia (healthy but a carrier) makes people less susceptible to malaria. In areas where the malaria is common, a higher number of people have the allele for sickle-cell anemia.

Question 41

Which of the following is an example of genetic drift and the founder effect?

A

Only twelve people, one of whom has a rare allele, survive a crash-landing on an uninhabited island. Four hundred years later, a huge proportion of the island's inhabitants have this rare allele.

B

A species of South American monkey is hunted to near extinction. One hundred years later, the monkeys' abundance has increased, but each individual is a near genetic twin of every other monkey.

C

A population of guppies in a large lake becomes divided when an earthquake causes a barrier to form, splitting the lake in half. Many generations later, the guppies in one half are all bright-colored and those in the other are all dull-colored.

D

Being heterozygous for sickle-cell anemia (healthy but a carrier) makes people less susceptible to malaria. In areas where the malaria is common, a higher number of people have the allele for sickle-cell anemia.

Question 42

Which of the following is NOT true of genetic drift?

A

It contributes to evolutionary change.

B

It can result in one allele representing 100% of the gene pool.

C

It can prevent the maintenance of Hardy-Weinberg equilibrium.

D

It results in populations of better-adapted individuals.

Question 43

Which of the following is true about mutation and recombination in sexually reproducing species?

A

Mutation and recombination are different terms for the same occurrence.

B

Mutations are often triggered by the recombination process and, in large populations, will then increase in frequency.

C

The effects of mutation and recombination are generally considered to be at odds.

D

In large populations, recombination can produce so much variation on its own that mutation is not necessary for hundreds of generations.

Question 44

Which of the following is true about random mating?

A

It appears to be quite common in nature.

B

It includes the process called "assortative mating."

C

It can prevent the maintenance of Hardy-Weinberg equilibrium.

D

It helps to ensure that gene frequencies remain constant over generations.

Question 45

Why do haploid organisms undergoing selective pressures change their gene frequencies (over generations) much more quickly than diploid organisms?

A

Haploid organisms produce more offspring than diploid organisms, meaning more individuals on whom selection can act are present.

B

Diploid organisms generate less variation in each generation, leading to less genetic variability on which selection can act

C

Haploid organisms have only one copy of each gene, which allows selection to act directly without recessive alleles being hidden in dominant phenotypes.

D

Diploid organisms have to reproduce sexually, which dilutes each individual's genomic material in the next generation.

Question 46

Why is neutral evolution important for those interested in determining the time that has passed since species shared a common ancestor?

A

The ratio of natural selection to neutral evolution can be identified and used to estimate evolutionary relationships.

B

The number of neutral mutations that are fixed over a given period of time can be predicted, and these can be used to estimate evolutionary relationships.

C

The number of times that genetic mechanisms were developed to repress certain types of mutations can be counted to estimate evolutionary relationships.

D

Neutral evolution is an important factor in evolutionary change, but it cannot be used to estimate evolutionary relationships.

Question 47

Why is sex (that is, being a sexually-reproducing rather than asexually-reproducing species) considered to be a benefit in terms of evolutionary forces and selection?

A

Sexual reproduction, and especially recombination, provides much more genetic variation on which any or all selective pressures can act.

B

Sexual reproduction dilutes the deleterious alleles of the heterogametic sex (the sex with two different sex chromosomes).

C

Sexual reproduction is not considered to be beneficial, but once it is present in a species it is too hard to select against.

D

Sexual reproduction leads to offspring being produced much more quickly, and the faster generation time leads to swifter evolutionary change.

Question 48

A group whose members all share a common ancestor and includes all species that share that common ancestor is:

A

Paraphyletic.

B

Monophyletic.

C

Polyphyletic.

D

Hemiphyletic.

Question 49

A group whose members all share a common ancestor but does not include all species that share that common ancestor is:

A

Paraphyletic.

B

Monophyletic.

C

Polyphyletic.

D

Hemiphyletic.

Question 50

Choose the type of speciation pattern exhibited in this example: A group of lizards has a range from Arizona through all of Central America. While populations that are close to one another can interbreed, populations in Arizona cannot breed with those from Honduras.

A

Allopatric speciation.

B

Sympatric speciation.

C

Parapatric speciation.

D

Adaptive radiation.

Question 51

Choose the type of speciation pattern exhibited in this example: Among a species of shrimp in a single reef, larger individuals exhibit a preference for one type of sponge host while smaller individuals exhibit a preference for another. Medium-sized shrimp (offspring of large and small shrimp) do not fit well into either sponge host and have a high mortality rate, and overall adults choose mates that are similar to them in size.

A

Allopatric speciation.

B

Sympatric speciation

C

Parapatric speciation.

D

Adaptive radiation.

Question 52

Choose the type of speciation pattern exhibited in this example: Tortoises in a single large population are separated by an earthquake that splits the area into several sections. Generations later, tortoises from one section cannot breed with those from another if they are brought into contact.

A

Allopatric speciation.

B

Sympatric speciation.

C

Parapatric speciation.

D

Adaptive radiation.

Question 53

Choose the type of speciation pattern exhibited in this example: A freak storm transports a population of fish to a large, distant lake. The lake has many uninhabited ecological niches, and some individuals exploit each of those niches. Over many generations, many different fish species have evolved from this initial species.

A

Allopatric speciation.

B

Sympatric speciation.

C

Parapatric speciation

D

Adaptive radiation.

Question 54

Name the type of isolation mechanism that is operating: Western deer-mice are unable to interact, or mate, with eastern deer-mice because the Mississippi River divides them.

A

Temporal isolation

B

Gametic isolation.

C

Behavioral isolation.

D

Habitat isolation.

Question 55

Name the type of isolation mechanism that is operating: Lollipop shrimp males would try to mate with candycane shrimp females, but the lollipop males' claws aren't the right shape to hold the candycane females during courtship/mating.

A

Habitat isolation.

B

Temporal isolation.

C

Mechanical isolation.

D

Gametic isolation.

Question 56

Name the type of isolation mechanism that is operating: Brain corals and fan corals in the same reef both release gametes (sperm and eggs) into the water at night, but the two don't come into contact because brain corals release their gametes when the moon is full and fan corals release theirs when the moon is dark.

A

Habitat isolation.

B

Temporal isolation.

C

Mechanical isolation.

D

Zygotic mortality.

Question 57

Name the type of isolation mechanism that is operating: Bullfrog males will try to mate with just about anything, including rocks (this is true), but when they fertilize the eggs of tree-frog females, the developing tadpoles die before they reach adulthood.

A

Mechanical isolation

B

Hybrid inviability.

C

Behavioral isolation.

D

Hybrid sterility.

Question 58

The definition of a species is:

A

A population of interbreeding organisms that does not or cannot breed with other populations, even given the opportunity to do so.

B

A cluster or organisms that is phylogenetically distinct from other clusters of organisms.

C

A cluster of organisms that is genetically distinct from other clusters of organisms.

D

All of these are proposed, and to some degree acceptable, definitions.

Question 59

Which is NOT true of cryptic species?

A

They are organisms that are evolutionarily diverse but morphologically indistinguishable.

B

They include many salamanders, ciliates, and the algae living in corals.

C

Cryptic species of bacteria have interchangeable housekeeping genes (core groups of genes).

D

They are extremely difficult to identify taxonomically without performing genetic analyses.

Question 60
question description

Consider this phylogenetic chart. Which group(s) give(s) live birth?

A

Groups 1-4

B

Groups 2-4.

C

Group 2.

D

Group 1.

Question 61
question description

Consider this phylogenetic chart. Which group(s) has/have an aquatic lifestyle, live birth, and no fins?

A

Groups 1 and 2

B

Group 2.

C

Groups 2-4.

D

Group 1.

Question 62
question description

Consider this phylogenetic chart. Which traits are possessed by members of group 3? (Make sure you choose the answer that lists all traits possessed by this group.)

A

Aquatic lifestyle and live birth.

B

Aquatic lifestyle and heterodonty (different types of teeth).

C

Aquatic lifestyle, live birth, fins, and a third eye.

D

Aquatic lifestyle, live birth, and fins.

Question 63
question description

For groups 3 and 4, what is the synapomorphy?

A

Live birth.

B

Fins.

C

Aquatic lifestyle.

D

Heteredonty.

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